Linux socket网络编程之聊天室（三）：select异步通讯实现

原文地址：http://blog.csdn.net/yeyuangen?viewmode=contents

1.服务器端

/*select_server.c 2011.9.2 by yyg*/#include <stdio.h>#include <stdlib.h>#include <errno.h>#include <string.h>#include <sys/types.h>#include <netinet/in.h>#include <sys/socket.h>#include <sys/wait.h>#include <pthread.h>#include <sys/wait.h>#include <sys/time.h>#include <arpa/inet.h>#include <unistd.h>#define MAXBUF 1024int main(int argc,char **argv){int sockfd,new_fd;socklen_t len;struct sockaddr_in my_addr,their_addr;unsigned int myport,lisnum;char buf[MAXBUF+1];fd_set rfds;struct timeval tv;int retval,maxfd = -1;if(argv[1]){myport = atoi(argv[1]);}elsemyport = 7838;if(argv[2]){lisnum = atoi(argv[2]);}elselisnum =2;if((sockfd = socket(PF_INET,SOCK_STREAM,0))== -1){perror("socket");exit(1);}bzero(&my_addr,sizeof(my_addr));my_addr.sin_family = PF_INET;my_addr.sin_port = htons(myport);if(argv[3])my_addr.sin_addr.s_addr = INADDR_ANY;if(bind(sockfd,(struct sockaddr *)&my_addr,sizeof(struct sockaddr)) == -1){perror("bind");exit(1);}if(listen(sockfd, lisnum) == -1){perror("listen");exit(1);}while(1){printf("\n----waiting for new connecting to start new char----\n");len = sizeof(struct sockaddr);if((new_fd = accept(sockfd,(struct sockaddr *)&their_addr,&len)) == -1){perror("accept");exit(errno);}elseprintf("server:got connection from %s,port %d,socked %d\n",\inet_ntoa(their_addr.sin_addr),\ntohs(their_addr.sin_port),new_fd);/*开始处理每个新连接上的数据收发*///printf("\n---ready to go.now you can chatting...input enter,then you can chat---\n");while(1){/*把集合清空*/FD_ZERO(&rfds);/*把标准输入句柄0加入到集合中*/FD_SET(0,&rfds);maxfd = 0;/*把当前连接句柄new_fd加入到集合中*/FD_SET(new_fd,&rfds);if(new_fd > maxfd)maxfd = new_fd;/*设置最大等待时间*/tv.tv_sec = 1;tv.tv_usec = 0;retval = select(maxfd+1,&rfds,NULL,NULL,&tv);if(retval == -1){printf("select error!%s\n",strerror(errno));break;}else if(retval == 0){//printf("no message come,user no press the button,please wait...\n");continue;}else{if(FD_ISSET(new_fd,&rfds)){/*连接的socket 上有消息则接收并显示*/bzero(buf,MAXBUF+1);/*接收对方发过来的消息，最多MAXBUF字节*/len = recv(new_fd, buf, MAXBUF, 0);if(len > 0)printf("recv msg success:%s! %d bytes rcv.\n ",buf,len);else{if(len < 0){printf("recv msg fail.the errno is:%d,error info is %s.\n",errno,strerror(errno));}elseprintf("quit.\n");break;}}// FD_ISSET = sockfd情况if(FD_ISSET(0,&rfds)){/*用户有输入了，则读取其内容并发送*/bzero(buf, MAXBUF+1);fgets(buf, MAXBUF, stdin);if(!strncasecmp(buf, "quit", 4)){printf("self request to quit the chating\n");break;}/*发消息给服务器*/len = send(new_fd, buf, strlen(buf)-1 , 0);if(len < 0){printf("mgs:%s send fail!errno is:%d,error info is:%s\n", buf, errno, strerror(errno));break;}else{printf("msg: %s\t send success, send %d bytes!\n", buf, len);}}//FD_ISSET = 0}//select 处理结束}/*内while*/close(new_fd);/*处理每个新连接上的数据收发结束*/printf("would you want to chatting with another one?(no->quit)");fflush(stdout);bzero(buf,MAXBUF+1);fgets(buf,MAXBUF,stdin);if(!strncasecmp(buf,"no",2)){printf("quit the chatting!\n");break;}}/*外while*/close(sockfd);return 0;}

2.客户端

/*select_client.c 2011.9.2 by yyg*/#include <stdio.h>#include <stdlib.h>#include <errno.h>#include <string.h>#include <sys/types.h>#include <netinet/in.h>#include <sys/socket.h>#include <sys/wait.h>#include <pthread.h>#include <sys/time.h>#include <arpa/inet.h>#include <unistd.h>#include <resolv.h>#define MAXBUF 1024int main(int argc,char **argv){int sockfd,len;struct sockaddr_in dest;char buffer[MAXBUF+1];fd_set rfds;struct timeval tv;int retval,maxfd = -1;if(argc != 3){printf("the param style wrong!\n");exit(0);}/*创建一个socket用于tcp通信*/if((sockfd = socket(AF_INET,SOCK_STREAM,0)) < 0){perror("socket");exit(errno);}/*初始化服务器端(对方)的地址和端口信息*/bzero(&dest,sizeof(dest));dest.sin_family = AF_INET;dest.sin_port = htons(atoi(argv[2]));if(inet_aton(argv[1],(struct in_addr *)&dest.sin_addr.s_addr) == 0){perror(argv[1]);exit(errno);}/*conect to the server*/if(connect(sockfd,(struct sockaddr*)&dest,sizeof(dest)) !=0){perror("connect");exit(errno);}printf("\n---ready to chatting...---\n");while(1){/*把集合清空*/FD_ZERO(&rfds);/*把标准输入句柄0加入到集合中*/FD_SET(0,&rfds);maxfd = 0;/*把当前连接句柄socket 加入到集合中*/FD_SET(sockfd,&rfds);if(sockfd > maxfd)maxfd = sockfd;/*设置最大等待时间*/tv.tv_sec = 1;tv.tv_usec = 0;/*开始等待*/retval = select(maxfd+1,&rfds,NULL,NULL,&tv);if(retval == -1){printf("select error,quit!\n");break;}else if(retval == 0){continue;}else{if(FD_ISSET(sockfd,&rfds)){/*连接的socket 上有消息则接收并显示*/bzero(buffer,MAXBUF+1);/*接收对方发过来的消息，最多MAXBUF字节*/len = recv(sockfd, buffer, MAXBUF, 0);if(len > 0)printf("recv msg success:%s! %d bytes rcv.\n ",buffer,len);else{if(len < 0){printf("recv msg fail.the errno is:%d,error info is %s.\n",errno,strerror(errno));}elseprintf("quit.\n");break;}}// FD_ISSET = sockfd情况if(FD_ISSET(0,&rfds)){/*用户有输入了，则读取其内容并发送*/bzero(buffer, MAXBUF+1);fgets(buffer, MAXBUF, stdin);if(!strncasecmp(buffer, "quit", 4)){printf("self request to quit the chating\n");break;}/*发消息给服务器*/len = send(sockfd, buffer, strlen(buffer)-1 , 0);if(len < 0){printf("mgs:%s send fail!errno is:%d,error info is:%s\n", buffer, errno, strerror(errno));break;}else{printf("msg: %s\t send success, send %d bytes!\n", buffer, len);}}//FD_ISSET = 0}//select 处理结束}//处理聊天的while 循环/*关闭连接*/close(sockfd);return 0;}

运行结果：

终端1：服务器端

[root@localhost net]# ./select_server 7838----waiting for new connecting to start new char----server:got connection from 172.31.100.236,port 59462,socked 4recv msg success:kfldsjfk! 8 bytes rcv.456354 msg: 456354         send success, send 6 bytes!recv msg success:453455! 6 bytes rcv.

终端2：客户端

[root@localhost net]#  ./select_client 172.31.100.236 7838---ready to chatting...---kfldsjfkmsg: kfldsjfk         send success, send 8 bytes!recv msg success:456354! 6 bytes rcv.453455 msg: 453455         send success, send 6 bytes!